Google Friend Connect, the popular service from Google allowing website owners to add social functions without coding to their websites, is expanding their service today to allow for a much deeper social experience.

Friend Connect is already a massive service, in use on some nine million websites. According to statistics sent to us by Google, there are 500 million 30-day unique viewers of pages using Friend Connect, and some two people join a site every second. That adds up to more than 170,000 sign-ups daily.

Today Friend Connect is launching several new features to expand on the already strong Friend Connect capabilities. For the user, interests can now be set to allow for better user to user interaction. If you love Metallica, and are on AlexWilhelm.com, for example, you would probably be more interested in meeting someone who also loves technology and heavy metal.

Along with that, Friend Connect now allows users to send private messages to each other. Before you raise your spam shield, this fits nicely with the interests features. Once you notice that one person on the obscure niche site you frequent, you are going to want to get ahold of them. Don’t worry, Google will connect you.

From the site owner end of things, Friend Connect just got a pile more useful. Once your users begin to fill out their interests, you can view the data in simple to digest graph form. All of a sudden you realize that indeed your readers love Megadeth more than Metallica. Well, for sure that will demand a change in the editorial track of your website!

Friend Connect also lets you send newsletters to your users, in batch email format. If you want to bring the sheep back to the fold, send out a note and explain the recent comings and goings-on in the site. Google wants to give the non-developers more control and options.

If you monetize your website with AdSense, Friend Connect will now let you add advertisements through Friend Connect, which will be synced with the stated interests of your users. Put more simply: better targeting means more clicks.

Finally, Friend Connect is launching the “personalized content gadget”. This tool brings a set of links to your content, tailored based upon what that user is interested in. This makes your site seemingly a perfect fit for that user, from their perspective, and makes your site much more sticky.

In totality, Google is launching a number of small upgrades that in aggregate add a much greater depth to Friend Connect. The service is already massively popular, and these upgrades will only add to the draw of the service. If you have not already, get ready to be a user on Friend Connect quickly.

Friend Connect seems to be the anti-Facebook. Instead of doing all the aggregation from external points to one central dumping point, Friend Connect wants to keep your presences separate, based on niche content. I have a suspicion that both have a space, and a future online. In their own words: “We’re excited to see the web evolve into a place where visitors of all websites can get to know each other — to share and discuss the things they care about most.”

If you use Friend Connect, or are going to begin to do so, drop a note in the comments with either what you are planning or are already doing.

Embedded below is a video prepared by Google outlining the new features.